Private-branch exchange sender circuit



1,559,251 R. w. HARPER PRIVATE BRANCH EXCHANGE SENDER CIRCUIT gag-E:

Filed June 13. 1924 3 Sheets-She et 1 To orunhrl TIL- Oct. 27 1925.

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Oct. 27, 1925. 1,559,251 R. W. HARPER PRIVATE BRANCH EXCHANGE SENDER CIRCUIT Filed June 13. 1924 3 Sheets-Sheet 3 Patented oct. 27, 1925.

ROBERT w. H RPER, or AST ORANGE, TRIO coMrANY, INCORPORATED, or

YOR

PRIVATE-BRANCH EXCIIANGE SENDER CIRCUIT.

Application filed Juneis, 1924. Serial No. 719,71l.'

To all whom it may concern:

Be it known that I, ROBERT V. HARPER, a citizen of the United Statesof America, residing at East Orange, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Private-Branch Exchange Sender Circuit, of which the following is a. full, clear, concise, and exact description.

This invention relates to telephone exchange systems and more particularly to automatic telephone exchange systems wherein series ofpulses are transmitted over a calling line to control the operation l automatic switches employed in establishing a connection.

lhis invention relates more. specifically to an improved requiring a minimum amount of an operators time for transmitting a series oi pulses for use at an Operators position in .a private branch exchange associated with an automatic telephone exchange system preferably of the type employing power driven switches of the revertive impulse type, the selective operations of which are controlled by registering mechanisms responsive ing to the wanted line designation transmitted over a calling line.

It is to be understood that this invention is not limited to automatic telephone exchange systems of the foregoing character but may be employed in private branch exchanges associated with automatic telephone systems of other types such as the automatic exchange systems wherein series of impulses transmitted over a calling line are employed for directly controlling the operation of its selective switches.

Hitherto in P. B. X. systems associated with automatic telephone exchange systems of the "foregoing character a dialimpulse sender has been provided at the P. B. X. operators position to enable the operator to transmit over the calling line, series of pulses corresponding to the designation of thewanted line communicated to the P. B. X. operator by the calling P. B. X. subscriber.

comparativel long period of time in which to send the series of'pulses required for reg i'stering the wanted line designation in the sender register. 7 W'hen it is considered that type of impulse transmitter to series of impulses correspond- Due to the nature of its structure the usual dial impulse sender requires a theprivate branch exchange operator usually has various other duties besides attending the switchboard it is deemed advisable that the time spent by the P. B. X. operator in transmitting series of pulses of wanted lirkre designations be reduced as much as pos- S1 e.

For this reason there is provided at the private branch exchange operators position a single set of digit keys on which the digits of a wanted line designation may be quickly and successfully written up and concurrently recorded ina unitary registering device of the coordinate switch type associated with the P. B. X. operators single set of keys. Thereafter uponthe operation of a startkeyjby the operator, series of impulses corresponding to the wanted line designation are transmitted to the register sender inthe automatic telephone exchange associated with the private branch exchange by means of an interrupter impulser, the number of pulses transmitted for each digit being determined by a set of'counting relays under the control of the corresponding registration set up in the registering mechanism. V I

It is the object of this invention to provide in a system of thefor'egoing character an impulse sending device for transmitting series of pulses corresponding to dial impulses in accordance with the registration set up in a unitary registering device of the coordinate switch type by the manipulation of associated keys.

A feature of the invention consists in the provision ofa single set of ten recording keys and a unitary registering device of the coordinate or cross-bar switch type capable vunder--the repeated manipulation of the recording keys ,to record allthe digits of a desired line designation.

A still further feature of the invention relatesto the provision with the abovementionedunitary registering device of the coordinate or cross-bar switch type of a single set of transfer relays for progressively associating the different register elements of the registering device with the recording keys and for progressively associating such register elements of the registering device with a set of counting relays employed for determining the number of pulses to be transmitted in any series-of pulses. 7

These and other features of the invention NEW JERSEY, AssIenoR To wEs 'RRN'RLRc- NEW YORK, N. Y., A CQRPORATION or NEW lit) will be more clearly apparent from a consideration of the following description taken in connection with the accompanying drawings and appended claims.

Referring to the drawings, Fig. 1 shows the cord circuit at a P. B. X. operators position having the plug 101 for answering calls incoming from a private branch exchange subscribers station 115, plug 110 for connection with a trunk outgoing to an automatic telephone exchan e, the emer ency dial impulse sender 125 and talking and dialing keys;

Fig. 2 shows the impulse interrupter 215 and its circuit, and the counting relays for determining the number of pulses to be transmitted in any series of impulses. Fig. 2 also shows in a schematic form the various automatic switches and the register sender used in establishing a connection from the outgoing trunk jack 210 to the called subscribers station 250.

3 shows the single set of recording keys 2311 to 320 having digit values of 1 to 0 respectively, the unitary registering device 300 comprising eight register elements corresponding to the eight digits of a wanted line designation and a single set of transfer relays 321 to 328 for progressively associating the register elements with the recording keys and the counting relays.

Fig. 1- shows the manner in which Figs. 1, and 3 should be arranged.

The registering mechanism disclosed in 2 is of: the coordinate or crossbar switch type and more particularly of the general type shown and described in detail in the patent to C. L. Goodrum, No. 1,551,- 024, issued Aug. 25, 1925. This switch consists of ten vertically disposed bars, each of which is controlled by a vertical magnet actuated in response to the depression of a key associated with it, and eight horizontal bars. Each of the horizontal bars is operated by a horizontal magnet individual thereto and shown at the left end of each bar, respectively. The number of horizontal bars may, however, be increased to include additional horizontal bars when it is desired to record digits in addition to the digits normally required for a wanted line designation.

Associated with each of the vertical bars are a number of contacts, each of which is arranged to connect the conductor associated with the vertical bars to a conductor individual to an operated horizontal bar. These contacts extend through micarta cards which are arranged to lift them into contact with the horizontal bar upon the conjoint operation of a vertical bar and a horizontal bar.

The chain of transfer relays shown in Fig. 8 serrcs as a. progression switch in conjunction with the horizontal magnets for The automatic teleohone line extendin equipment shown in schematic form on Fi 2 consists of a numbe' of selector switches and a register sender for controlling the operation of the automatic switches, preferably of the well-known panel type such as disclosed in Patent 1,395,977, issued to F. A. Stearn and F. J. Scudder, November 1, 1921.

The relays and magnets of the registering mechanism and impulse circuit are operated by common battery potential.

It is believed t1 at the invention will be best understood from a detailed description of the manner in which the apparatus functions.

In response to a signal (not shown) of a calling P. B. X. subscriber, the P. B. X. operator inserts the plug 101 of her cord into the answering jack 102 and operates her talking key 103, thereby establishing a talking connection between the calling subscriber and P. B. X; operator. This talking connection may be traced from the tip side of the operators telephone set (not shown), outer right back contact of relay 107, outer upper contact of key 103, inner normal contact of key 106, upper left winding of repeating coil 10 1, left and inner right back contacts of relay 108, winding of relay 109, lower left winding of repeating coil 10st, inner lower normal contact of key 106, lower contact of relay 103 to the ring side of the operators telephone set. The circuit from the right windings of the repeating coil 10% to the calling subscribers station may be traced from grounded battery lower right winding of repeating coil 10 i, lower contact of key 106, winding of relay 112, ring of answering plug 101 and answering jack 102 through the calling subscribers station 115, tip of answering jack 102 and plug 101, outer upper normal contact of key 106 to ground through the upper right winding of repeating coil 1( -i-. In operating key 103 a circuit is completed for operating relays 105 and 20.1 from grounded battery, winding of relay 105, middle upper alternate contactof key 103, conductor 122, left back contacts of relay 202, conductor 220 to ground through the winding of relay 201. Relay 201 in operatingprovides ground at its right, front contact for operating the vertical magnets upon the depression of the recording keys and at its left front contact 207 which may be traced from grounded battery, left front contact of relay 201, resistances 208 and 209 in series to ground on the front'contact of relay 205. i The 0ifnormal lamp 207 remains unlighted until the operation of the registering mechanism as described later herein.

Assuming the line wanted by the calling P. B. X. subscriber is designated BEL 2483VV, the P. B. X. operator successively depresses non-locking digit keys 312, 313 and 315 for setting the code registration in the registering mechanism, it having been assumed that the code is BEL, which have a digit value of 2,-3 and 5 respectively, and

the keys 312, 314,- 318 and 313 which have a digit value of 2, 4, 8- and 3 respectively for setting the numerical registration and the key 319 for setting the stations registration, since we have assumed the stations designation to be V which has a digit value of 9.

Upon the depression'of key 312'for the first letter B oftlie code a circuit is completed for energizing vertical magnet 302 from grounded battery, winding of vertical magnet 302, spring contact of key 312, conductor 341 to ground on the right front contact of relay 201. Vertical magnet 302 attracts its armatures, rotates the associated vertical bar'of the register associated there- 'with and establishes a circuit for operating horizontal magnet 321 from ground on the lower front contact of vertical magnet 302, conductor 343, right back contact of transfer relay 331, winding of horizontal magnet 321, conductor 342 to grounded battery. Vertical magnet 302, in operating, also completes a locking circuit for itself before the operation of horizontal magnet 321. This circuit extends from grounded battery through the winding and inner'front contact of vertical magnet 302, conductor 345, left back contact of horizontal magnet 321,

right back contact of transfer relay 331, conductor 343 to ground on the outer. front contact of vertical magnet 302. Vertical magnet 302 in completing a locking circuit for itself assures the operation of horizontal magnet 321 in the event that the-release of key 312 opens the initial energizing circuit of vertical magnet 302 before the operation of horizontal magnet 321. Horizontal magnet 321 operates and rotates the horizontal bar associated therewith which, in conjunction with the vertical bar, operates the card 351 located at thejunction of the two op'erated bars in the well known manner, thereby cording the second letter of the code.

setting the register for the first letter code.

, Horizontal magnet 321, in operating, completes at its left front contact, a locking circuit for itself from grounded battery, conductor 342, winding and left front contact of horizontal magnet 321, winding of ti the transfer relay 331,'conductor' 344 to ground 7 onthe outer right back cont-act of relay 204 but relay 331 does not operate in this circuit until ground is removedat the contact of magnet 302. Horizontal magnet 321, upon operating, also opens at its leftback contact the locking circuit of vertical magnet 302 causing it'to release and restore its associated vertical rod. Card 351 is held operated by its horizontal bar while horizontal magnet 321 remains operated. As soon as magnet 302 'deenergizes, relay 331 'energizes'in the locking circuit of magnet 321, opening at its right back contact the initial energizing circuit of magnet 321 and at its rightfront contact prepares a circuit for operatinghorizontal magnet 322 associated with the register elements for registering the second letter of the code.

When horizontal magnet 321 is operated,

the circuit through its right back contact for energizing relay 205 is opened. releases and in so doing opens the shunt Relay 205 circuit around lamp 207. Lamp 207 is lighted and continues so until the register mechanism is returned to normal.

Upon the depression of key 313 for letter E, the second letter of the code, a circuit is completed for energizing vertical magnet 303 from grounded battery, winding of vertical magnet 303, spring contact of key 313 to ground on conductor 341. Vertical magnet 303, in operating, completes a looking circuit for itself for assuring the operation of horizontal magnet 322 in a manner similar to that described for locking vertical magnet 302 to assure the operation of horizon tal magnet 321. Vertical magnet 303 also ro-' tates the vertical bar associated therewith and establishes a circuit for operating horizontal iiiagnet 322 associated with the register elements of the registering mechanism for rei The C11C111l3 fOIilOIlZOIltitl magnet 322 may be traced from ground, lower front contact of vertical magnet 303, conductor 343, right front contact of transfer relay 331, right back contact of transfer relay 332, winding of horizontal magnet 322, conductor 342 to grounded battery. Horizontal magnet 332,

- in operating, rotates the horizontal bar associated therewith, which, in conjunction with the operated vertical bar, operates the register card 352 located at the junction of the two operated bars in thewell known manner, thereby setting the register for the second letter of the code I v lVhenhorizontal magnet 322 operates,-it

completes at its left front contact, a look ing circuit for itself which may be traced from grounded battery, conductor 3 12, winding of and left front contact of hori zontal magnet 322, winding of transfer relay 332, conductor 34a to ground through the outer left back contact of relay 204-. Transfer relay 332 does not operate in this circuit until after the release of vertical magnet 303, since its winding is shunted through the contact of magnet 303. I-Iorizontal magnet 322, in operating, opens the locking circuit for vertical magnet 303 at its left back contact after it has completed its locking circuit at its left front contact. Card 352 is held operated by its horizontal bar while horizontal magnet 322 remains operated. Following the release of magnet 303, transfer relay 33 2 operates in the locking circuit of magnet 322, opening the initial energizing circuit of magnet 322 and prepares a circuit at its right front contact for operating magnet 333 associated with the register elements for registering the third letter of the code.

Upon the depression of key 315 for L, the third letter of the code, which has been assumed to have a digit value of 5, vertical magnet 305 and horizontal magnet 323 are operated and rotate their respective asso ciated bars, which, in conjunction with each other, operate the card located at the junction of the operated bars, thereby completing the registration of L, the third letter of the code, in a manner similar to that described for registration of the first and second letters of the code. As a result of the operation of horizontal magnet 323, transfer relay is operated and associates the register elements for registering the thousands digit with the recording keys in the same manner as previously described in the operation of transfer relay 331.

In response to the successive depression of keys 312, 31 1, 318 and which have a digit value of 2, 1, 8 and 3 respectively as previously recited, the magnets 302 and 32%, 304- and 325, 303, and 326, and 303 and 327 are successively operated and rotate their associated lars to operate cards 354, 350 and 357 to set a thousands register element, a hundreds register element, a tens register elementand :1 units register element respectively.

The hundreds register element, tens register element, units register element and the stations register element are successively associated with the recording keys in a manner similar to that previously described for associating the thousands register element and the register elements for the letters of the code with the recording keys.

Upon the depression of key 319, it having been assumed that the stations designation is XV with a digit value of 9, vertical magnet 309 and horizontal magnet 328 are operated to rotate their associated bars to operate thecard 358 to register the stations registl a tion in the same manner as previously described for the operation of preceding cards. Transfer relay 33S operates upon the, operation of horizontal magnet 328 and disasseciates the stations register elements from -the recording keys. The recording keys are now disassociated from every register ele ment of the registering mechanism. r

The registration of the designation of the wanted line having been completed, the operator inserts the plug 110 of her cord 130 into the jack 2100f the trunk outgoing to the automatic exchange.

The insertion of the plug 110 into the jack 210- completes a circuit from ground, high resistance 212, sleeve of jack 210 and plug 110, conductor 126, through the windings of marginal relay 108 and sensitive relay 114 in series to grounded battery. Relay 114 operates in this circuit but marginal relay l08 is not operated due to the presence of high resistance'212 in the circuit, Marginal relay 108 is operated only when the plug 110 of the cord 130 is inserted into the jack of a local P. B. X. subscribers line and hence its operation is not described herein, since the establishment of a connection to a local P. B. X. subscribers line is not an essential part of this invention.

After having recorded the wanted designation on her keyboard and having plugged into the jack 210 of the outgoing trunk, the operator depresses the start key 211, which completes an obvious circuit for operating relay 203. Relay 203, in operating, completes at its outermost left contact and left armature a circuit for operating marginal relay 105 in the operators cord circuit. This circuit may be traced from grounded battery, winding of relay105, upper middle contact of key 103, conductor 122, left back contact of relay 202 to ground on the outermost left front contact and outer left armature of relay 203. lifarginal relay 105 operates and relay 201 releases at this time since ground at the outer left front contact of relay 203 shunts out the winding of relay 1 201. The operation of relay 203 completes a circuit at its inner left contact for retaining the off-normal lamp 207 lighted after relay 201 is released. The release of relay 201 removes opera-ting ground from conductor 34 1 in order to render subsequent accidental depressions of the keys ineffective.

When relay 105 operates, a circuit is completed for operating relay 202 from grounded battery on the inner left hand arn'iat rre and innermost front contact of relay 203, winding of relay 202, conductor 12%, upper inner front contact of relay 105, upper middle contact of relay 103', conductor 122, left mea contact of relay 203, left back contact of" relay 204, conductor 123, lower inner front contact of relay to ground onthe front contact of relay 114. Relay 202, in operating, completes a locking circuit for itself by closing its left front contact before opening its left back contact from grounded battery on the innermost leftfront contact of relay 203, winding and left front contact of relay 202 to ground on the left front contact, of relay 203. Relay 202, in closing its left .front contact,also completes a locking circuit for relay 105, which may be traced from grounded battery through its winding and upper inner front contact, conductor 124, left front contact of relay 202 to ground on the outer left armature of relay 203.

' Relay 105, in operating, connects the fundamental interrupter impulser circuit through the tip and ring of the outgoing trunk to the sender inthe automatic exchange. This circuit maybe traced from the sender through the tip ofjack 210 and plug 110, conductor 128, upper outer front contact of relay 105, leftclosed contact of unoperated emergency key 111, conductor 121, outer left back contact of relay 206 and closed interrupter contact 217 in parallel, conductor 120, right closed contact of unoperated emergency 'key'111, lower outer front contact of relay 1105, conductor 127, ring of plug and jack 210 to the sender. I p

.VVhen relay 203 operates it completes a circuit for operating slow release relay 219 from grounded battery on the inner right back contact of 0' counting relay 230, winding of slow release relay 219to ground on the outer left contact of relay 203. The operation of relay 219 'prepares'at its right front contact 'a circuit for operating relay 213 upon the next closure of contact 216 of the constantly rotating interriupter 215. hen interrupter contact 216 closes, relay 213 operates in a circuit from grounded battery on the inner right back contact of 0' counting relay 230, right front contact of relay 219, winding of relay 213, inner left back contact of relay 206 to ground through closed interrupter contact 216. Relay 213, in operating, completes an obvious circuit for operating relay 214 to provide ground for holding the counting relays land 1 to 0 and 9 after they have been operated. At its left front contact relay 213 completes a locking circuit for itself through its winding, as previously described, and the wind-.1 ing of slow operating relay 206 in seriesto ground on its left front contact. During the Closure of i terr p er roatact 'glerel y 2 6 remains unoperated due to the fact that its.

Winding'is shunted by ground on'the inter rupter contact 216;over its left inner back contact.

When interrupter contact 216 is opened, the shunt'around the winding of slow operating relay 206 is removed'and relay 206 thereupon operates. Immediately after the opening of interruptcr contact 216,'interrupter contact 217 [closes and in so doing closes the fundamental circuit before slow operating relay 206 can open the funda;v mental circuit at its outer left back contact. Relay 206 is designed as a slowoperating relay in order to assure the closure of interrupter contact 217 after the opening of mterrupter contact 216 before relay 206 can operate to open the fundamental circuitat its outer left back contact.' Otherwise, the

fundamental circuit would be opened for a short period and a false pulse transmitted overthe line upon the closure of interrupter contact 217 after the opening of the outer left back contact of relay 206. I 7

With relay 206 operated, a circuit is prepared upon the neXt closure of interrupter contact 216 for operating the counting relay corresponding to the registration set up by a register element of the registering mechanism for the first letter of the code. When interrupter contact 217 next opens, the fundamental circuit is opened since relay 206 is operated and its outer left back contact is open. hen interrupter contact 216 next closes after the opening ofinterrupter contact 217, sufiicient current passes through the winding of relay 206 to hold relay 206 operated. With interrupter contact 216 closed at this time, a circuit is completed from grounded battery, winding of the'No.

l'counting relay 221, outer right back con-.

tact of 'No 1 counting relay 231, conductor 362, contact of card 351, conductor 371, right front contact of horizontal magnet 321, conductor 346, inner front contacts of relay 206 to'ground through closed interrupter contact 216. The No. 1 counting relay 221 operates and at its left front contact completes a locking circuit for. itself from grounded battery through its winding and the winding of the N0. 1 counting relay 231 in series, the left front contact of the No. 1 counting relay221 to ground on the outer left front contact of relay 214. The No. 1 counting relay fails to operate in this circuit at this itime due to its winding being shunted by ground through the interrupter contact 216. I When interrupter contact 216 next opens, the shunt around the winding of the No. 1 counting relayis removed and this counting relay operates ov'er the'circuit previously described. Following the o ening *ofinterrupter contact 216, the fundamental circuit is again closed by the closing of interrupter nta 2 and a pulse thus eeat-ran:

' mitted over the outgoing trunk and recorded in the sender of the automatic exchange.

The No. 1 counting relay 231 in operat ing completes at its front contact a circuit for the No. 0 counting relay 220 as soon as the interrupter contact 216 again closes. This circuit may be traced from battery through the inding of relay 220, the outer right back contact of relay 230, the front contact of relay 231, conductor 362, thence to ground through interrupter contact 216 as previously traced. Relay 220 operates and at its right contact completes a locking circuit for itself from grounded battery through its inding and the Winding of the No. 0." counting relay 230 in series, the right front contact of relay 22Q to ground on the leftfront contact of relay 219. The No. 0 relay does not operate in this circuit until the next opening of contact 216.

lVhen interrupter contact 216 next opens, the shunt around the winding of the No. 0 counting relay is ren oved and this relay operates. Following the opening of interrupter contact 216, the fundamental circuit is again closed by the closing of interrupter contact 217 and a second pulse of the first code series is thus completely transmitted;

The No.1 0" counting relay 230, in operating, com letes at itsleft front contact a short circuit of the fundamental circuit so as to render the action of interrupter 215 ineffective to transmit further impulss for the time being. Counting relay 230, in operating, by removing grounded battery at its inner 'i'ight bacli' contact, opens the operating circuits of slow release relay 219 and relays 2.13 and 206 causing their relea e y 1. re /sw ne, causes th release, of relay Relay 21 4, upon releasing opens the circuits of relays and 23.1. Relay 206, in releasing, again closes the fundamental circuit at its outer left back Contact. Relay 219, in releasing, opens the loclring circuits Qfllllfl operated counting relays 220 and 230, thereby causing th 'ir release. llelay 21$), is designed as a slow release relay to assure, the release, of relay 206 and the. closing of the fim dainental circuit.- at the outer left back contact of relay 206 before counting relay 23 0 releases and opfns the short circuit on the fiuidamental circuit in order to render the. action of the impulse interrupter 2.15 inetfectiveto interrupt the fundamental circuit this time. hen counting relay 230 Was operated, a circuit was connaleted, forv shunting thehorizontal magnet 32], and causing its release. This circuit may be traced from grounded battery on the right front contact of counting. relay 23.0, conductor 34:7,, "inner left front contact. of transfer relay. 331, Winding of relay 331, conductor 3 1 1 to ground on the outermost right back contact of relay 204. Horizontal magnet 321 is shunted by this circuit since it will be recalled that battery for energizing this magnet is derived from the same source connected to conductor 3 12. The release of horizontal magnet 321 restores its associated horizontal bar and register card 351 to their normal positions.

Horizontal magnet 321, in releasing, opens at its left front contact the initial energizing circuit of transfer relay 331 and at its right back contact prepares a circuit for associating the interrupter impulser cir cuit with the counting relays in accordance with the setting on the register elements for the second letter of the code.

hen counting relay 230 releases, it opens the energizing circuit of transfer relay causing it to release since its initial'energizing circuit is opened upon .the release of the horizontal magnet 321,

It will be observed that the fundamental circuit was only opened twice before the operation of the Q counting relay and that the pulses caused by twice openingtl e fundamental circuit correspond with the as sumed value of letter B, the first letter of the code. 7 i

The pulses for the first letter of the code having been transmitted overthe line, the interrupter impulser circuit prepares to transmit the series of pulses for the second letter of the code under the control of the counting relays, determined by. the registrat ion set up by a second registerelement of the registering. mechanism in the same manner as described for sending the'pulses for the first letter of the code. Upon the release of counting relay 230, relays 219,206, 213 and 21st are operated as previously described. Vith relay 206 operated, upon the next opening of interrupter contact 217, the fundamental circuit opened. Upon the subsequent closure of interrupter contact 216, a circuit is completed from grounded battery, Winding of the No. 2 counting relay 22 2;, back contact of the No. 2 counting relay 232, conductor 3,63 contact of card 352, conductor 372, right front contact of horizontal Inagnet 322- and right back contact horizontal magnet 321 in series, conductor 35.1;6, inner front contacts of relay 20.6 to ground through interrupter contact 216. The e. 2 counting relay operates and at its left front contact completes a locking cir cuit for itself to ground on the outer left front contact of relay 214. The No. 2 counting relay fails to operate in this circuit since its Winding is shunted by ground on the, interrupter contact 216. Upon the subsequent opening of interrupter contact 216, the No. 2" counting relay operates and is locked up over the circuit for holding the No. 2 counting relay. Upon the subsequent closing of interrupter 21?,fthe circuit is again closed and the first pulseof fundamental circuit. closure of interrupter contact 216, theNo.

the series of pulses corresponding to -the the fundamental circuit since relay 206 is held operated as previously described. \Vhen', interrupter contact 216 closes following the opening of interrupter contact 217, the No.-

1 counting relay is operated overa circuit including the right front contact of the'No. 2 counting relay to groundon interrupter contact 216 as previously described and com pletes a locking circuit for itself through its left front contact to ground on the outer left front contact of relay 214. WVhen inter;

rupter contact 216 again opens, the No. -1

counting relay is operated and completes a circuit for operating the No. 0 counting relay upon the next closure of interrupter contact 216. After the opening of interrupter contact 216, interrupter contact 217 again closes, and in so doing again closes the fundamental circuit; Interrupter contact 217 again opens, and in so doing opens the Upon the subsequent 0 counting relay is operated over a circuit including the right front contacts of the No. 1 and 2 counting relays to groundl on interrupter contact 216 as previously described and completes a locking circuit for itself through its right frontcontact to ground on the left front contact ofrelay 219. Upon the following opening of interrupter contact 216, the No. 0 counting relay is operated and locked up over the same circuit for holding the No. 0 counting relay.

The No. 0 counting relay, in operating, completes at its leftfront contacta short circuit for the fundamental circuit so as to render the action of the interrupter 215 ineffective to transmit further pulses over the fundamental circuit for the time being. U 3011 the operation of the No. 0 counting relays 219, 206, 213 and 214 are released as previously described. Relay 214 in releasing removes holding ground from the circuits of counting relays 221, 222, 231 and 232, causing their release. Relay 206, in releasing, closes at its outer left back contact the fundamental circuit. Slow release relay .219 releases, and in so doing opens at its left front contact the energizing circuits of counting relays 220 and 230, causing their release. Relay 219'is designed as slow releasing in order to permit relay 206 to re lease and close the fundamental circuit before the release ofthe N0. 0' counting relay mit pulses until after the next operation of relay 206. 4 I i hen the No. 0 counting relay operates itcompletes at its right front contact a circuit for shunting horizontal magnet 322 causing it to release. This circuit may be traced from grounded battery, right front contact of the No. 0 counting relay, conductor 347, left back contact of transfer relay 331, inner left front contact of transferrelay 332, conductor 344 to ground on the outer right front contact of relay 204. Horizontal magnet 322 deenergizes and prepares at its right baclrcontact a circuit forassociating the register element for the third letter of the code with the interrupter im pulser circuit. The release of horizontal magnet v 322 restores its associated horizontal bar and'register card 352 to normal. I n

It will be noted thatinterrupter contact 217 opened and closed three times after the operation of relay 206 to transmit three pulses over the fundamental circuit corresponding to the assumed value of the second letter of the code E before the operation of the No. 0 counting relay renders the opera tion Of'tlle interrupter 215 ineffective to transmitfurther impulses 1 for the second letter of the code.

In 'a manner similar to that described for the transmission of the series of pulses for the first and second lottersiofjthe' code, the interrupter impulse circuit is progressively associated with the register element for the third letter of the code, and With the register elements for the thousands,hundreds, tens, units and stations designations. Series of five pulses for the third letter of the code, series of two, four, eight and three pulses for the thousands, hundreds, tens and units designations, respectively, and a series of nine pulses for the'station designation V which Was assumed to havea digit value of nine, are transmitted over the outgoing trunk to the sender in the automatic exchange in accordance with the registrations recorded at the respective register elements; Followingthe transmission of the series, of pulses forthe third letter of the code and for the thousands,hundreds, tens, units and stations designations, the horizontal magnets 323, 324, 325, 326, 327 and 328, respectively are released and restore their respectively associated horizontal bars and register cards 353, -4, 356, 357 and to normal in a manner similar to that deios scribed in connection with the release of I horizontal magnets 321 and 322 after the transmission ofseries of pulses forthe first and second letters of the code.

After the transmission of the station designation series of pulses, relays 219, 213, 206 and 214 .are operatedxin the same manner as previously .described after the transmission of the series of pulses for the first and second letters of the code.

U pen the re'leaseof horizontal magnet 328 after the transmission of the series of pulses for he station designation a circuit isestablis led froln ground on the right back con tact of horizontal magnet 328, right back contacts in series of allother horizontal magnets, conductor 351-6, right back Contact of relay 206, right front contact of relay 202 to grounded battery through the wind mg of relay 218. Relay 218 operates in this circuit and provides a locking circuit for itself through its left armature and outer contact to ground at the outer left contact of relay 203 and completes a circuit for operation relay 204- from grounded battery, winding of relay 204, through the inner left front contact of relay 218 to ground at the left armature of relay 203. Relay 204 in operating opens its right back contacts to remove ground from the energizing circuits of the transfer relays but has no effect at this time since the transfer relays are deeiiergized. Relay 2041 in operating opens at its left back contact the locking circuit of relay 203 causing it to deenergize.

The release of relay 203 opens the operating circuit of relay 219 causing it to release and in turn to release relays 206 and 213. The release of relay 213 effects the release of relay 2l4 which in turn causes the release of all the counting relays locked to ground on the front contacts of relay 2141. Relay 203 in releasing removes ground from the energizing circuits of relays 218 and 204:. Relay 201 releases but relay 218 does not release until its initial energizing circuit is openedupon the release of relay 02.

As soon as relay 203 releases, the shunt circuit around the winding of relay 201 is removed and relay 201 is thereupon 0perated. Marginal relay 105 releases because of the presence of the winding of relay 201 in the circuit which may be traced through either the left front contact or the left back contact of the muke-before-break spring contact combination of relay 202 depending upon whether at this instant, relay 202 is still operated or released following the re lease of relay 203.

Relay 203 in releasing removes ground from the operating circuit of relay 202 causing it to release. The release of relay 202 opens the initial energizing circuit of relay 218 causing its release. lVith relay 202 released a circuit is completed from grounded battery on the left front contact of relay 201, through the winding of relay 205, right back contact of relay 202, right back contact of relay 203, conductor to ground through the right back contacts of the hori zontal magnets in series. Relay 205 operates and at its right from contact completes a shunt circuit for extinguishing the oftnormal lamp 207. Relay 201 in operating provides ground at its right front contact for operatingthe vertical magnets upon the depression of the recording keys for the nest wanted line designation.

Relay 1 05 in releasing detaches at its upper and lower outer front contacts the register sending mechanism from the cord 130 and at its upper lower outer back contacts cuts the talking conductors of the cord 130 through to permit the P. B. X. calling sub'scriher to converse with the called subscriber upon the establishment of the talking connection in the automatic exchange.

When the P. B. X. operator sees that the off normal lamp 207 is extinguished, she restores the talking key 103 thereby removing grounded battery from the operating circuit of relay 201. Relay 201 releases and in so doing causes the release of relay 205.

Associated with the operators cord 130 are the usual supervisory relays 112 and 113 and the supervisory signal lamps 116 and 11'? associated therewith respectively. When the P. B. X. subscriber at station 115 restores his receiver, a circuit through supervisory relay 112 is opened causing it to dee'nergize to complete a circuit for lighting lamp 116 whereupon the P. B. X. operator removes the plug 101 of the cord from the answering jack 102 and extinguishes the lamp 116.- If after the called subscriber in the automatic exchange has restored his receiver, the calling P. B. X. subscriber fails to hang up, and a call is incoming from the automatic exchange over the trunk with which the trunk cord 130 is connected, a circuit for operating relay 113 is completed in the manner well known in the art. Relay 113 now completes an obvious circuit for lighting lamp 117. When the P. B. X. operator observes that signal lamp 117 is lighted she operates the talking key to connect her head set to the line incoming from the automatic exchange and ascertains from the calling subscriber the number of the desired P. B. X. subscriber. Having ascertained the desired number she removes the plug 101 from jack 102 and inserts the plug 101 into the jack of the desired P. B. X. subscriber after which she releases the talking key 103.

If while the off-normal lamp 207 is lighted indicating that the impulse sending mechanism is still in use, the operator observes that signal lamp 116 is operated indicating that the calling P. B. X. subscriber has disconnected, the operator rethe sender in the automatic exchange by removing plug 110 from the outgoing trunk jack 210. The removal of the plug 110 from the outgoing trunk jack 210 sets up the well known wipe out condition in operating wipe out key 2 11"which com-' pletes -an.- obv ous circuit for operating release. relay 218. Relay. 218 'in operating completes a circuit for operating relay1-2041 from grounded battery, inner left front contact of relay 218, to ground at the'outer left front contact of relay 203. Relay 201 operatesandin so, doing opens at its right back contacts the locking circuits of all thehorizontal magnets and transfer relays causing them toirelease. vT-h'e release of the horizontal magnets restores their associatedhorizontal bars and the operated registeri'cards to normal. In the manner similar .to-:that previously described for restoringtheimpulse interrupter circuit to 'normal :after the release of the horizontal .isrestored to normal.

magnet-328, the impulse interrupter circuit" I r v 7 Vtransm1t1t1ng .means, and means under the 'llheoperatormay cause a"wipeout con-.

dition in the sender of the automatic exchange and'the'immediate restoration of the impulse sending mechanism upon the calling PrBpXy subscriber disconnectingbefore station' designations series of impulses are transmitted by operating the wi pe out key 211 and restoring thetalking key 103. 'l h'e operation' oft-he wipe out key 2 11 causes the =restoration of the' interru-pter impulse sending mechanism in the -same 'rnanner as that previously described: The release ota'elay 203 during the restoration'of the interrupter impulse sending mechanism causes the operation of relay 201- and the consequent release of relay 105. j Therelease-of relay 105, however, does not effect the wipe out condition of the sender of the automatic exchange since the closure of theback contacts of the make-befo're-break spring contact combinations of relay" 105 completes a loop circuit which maybe traced from the tip side 128 of the plug:

110 and jack 210, upper back contact of relay 105, uppermost closed contact of talking key 103 to the tip side'of the operators head set through the outer right back contactof relay 107, ring side'ot the operators head set, lower closed contact of the talking-key 103, lowermost back contact of relay 105, ring conductor "127, ring side of plug 110 and jack 210 to thesender in the automatic telephone exchange. However, when the loperator restores her talking key this loop circuit is opened and the v wipe out condition iscaused in the sender.

: I'f for-any reason the impulse sending mechanism associated with the registering mechanism and keyboard fails to properly functiomthe PQ-B.'-X. operator operates the emergencykey 1-11 which detaches theregistering impulse sending mechanism from and connects the dial impulse sender 125 with the cord 180 for sending outvdial pulses in a manner well known in the art.

\Vhat isclaimed isz KLAn impulse sending mechanism com-. prising a set of recording keys representing the several digits of a decimal system, a unitary registering mechanism of the cross? bar switch type adapted to set up a registration: in accordanceiwith the digits recorded Jon. said recording keys, and means under the gcontrol of said registering mocha nismufor transmitting series of pulses corresponding; to the digits -recorded onsaid recording keys. 0 i I i Animpulse sending mechanism comprisinga set of recording keys representing the :severaldigits of a decimal system, a unitary registeringmechanism of the crosscorded on said recording keys, impulse control of the registration. set up=in saidunitaryfregistering mechanism to cause said corded on said recording keys.

3.-Ani impul'se sending mechanism com prising a set of recording keys representing theseveral digits of a decimal system," a unitary registering mechanism of-the cross bar switch type't'or registering the digits recorded on said keys, a start key,-1neans for transmitting pulses'over a circuit in re sponse torthe operation vof said start key and means under the control of said unitary registering mechanism to cause said transmitting means to transmit said pulses over said circuit in series correspondingto the di-gits'recorded on said recording keys.

4; An impulsese'nding mechanism comprising'a set of recording keysrepresenting the several digits of a decimal system, a unitary aregistering mechanism of the I coordinate switch type adapted to set up regin series corresponding towthe digits reistrations in accordance with the digits re-' corded on said recording keys, a start key,-

means 'for transmitting pulses over a circuit 1n"; response to the operation of said start recorded on said recordingkeys.

M5.-=An impulse sending mechanism comthe; several dig-its of a' decimal system, a unitary registering mechanism of the coordinate switch. type for registering the digits recorded on the I recording keys, impulse last mentioned means to transmit said pulses ,prisingi'asettof recording-keys representing transmitting means comprising a constantly rotating interrupter for interrupting a closed circuit, means-for normally shortcircuiting said interrupter for rendering it ineffective to interrupt said closed circuit, a start key, means operative in response to the operation of said start key to open said short circuit, and means including a set of counting relays operative under the control of said unitary registering mechanism for causing said impulse transmitting means to transmit series of pulses corresponding to the digits recorded on the recording keys.

6. An impulse sending mechanism comprising a set of recording keys representing theseveral digits of a decimal system, a unitary registering mechanism forregistering the digits recorded on said recording keys, impulse transmitting means comprising a constantly rotating interrupter for. interrupting a closed circuit, means for normally shortcircuiting said interrupter for rendering it ineffective to interrupt said closed circuit, a startkey, means responsive to the. operation of said start key to open sa'idshort circuit to render said interrupter effective .to interrupt said closed circuit, and means for thereafter intermittently short-circuiting, said closed circuit under the control of. said unitary registering mechanism to render said interrupter ineffective to transmit series of pulses corresponding to the-digits recorded on. said recording keys.

7. In a telephone system, an impulse transmitter including a key adapted for successive actuation to set up the same: digit a plurality of times and a registering mechanism of the cross-bar switch type for registering the digits set up.

8. In a registering; mechanism the combination of a single set of recording. keys representing the several digits of a decimal system and a registering mechanism of the cross-bar switch type for successively registering the digits recorded on said recordingkeys.

9. In a telephone exchange system, an impulse transmitter including a single set of recording keys representing the several digits of the decimal system, a-unitary registering mechanism of the-cross-bari switch type having a plurality of groups of register elements for registering the digits recorded on said recording keys, and. means for progressively associating each of said plurality of groups of register elements with said recording keys.

10. In a telephone exchange system, an impulse transmitter incl'uding aisingle set of: recording 1. keys, a unitary registering mechanism of. the cross-bar. switch type, said registerihaving a=,plurality of groups of regis'terelemcnts one of which is normally associated with said recording keys foil-registering the first digit of a line designation and means for progressively associating each of the other groups of 'said register elements with said recording keys for registering the succeeding digits of said line designation.

1].. In a telephone exchange system, an impulse transmitter including a singleset of recording keys, a unitary registering mechanism of the cross-bar switch type, said registering 'mechanism having a plurality of groups. of register elements .one of which is normally associated with said recording keys for registering the first digit of a line designatiomand means operativenpon the registrationof a digit of 1a linedesignation to associate the next. succeeding group .of said register elements with said recording keys.

12. In a telephone exchange--system,;an impulse transmitter including. a single-"set of recordingkeys, a unitary registering mechanism of the cross-bar switchv type said unitary registering mechanism havingz: a plurality of groups ofreg-ister elements for registering the digits of line designations recorded onisaid recordingkeys, one of said register elements normally-associated with said recording ,keys and arranged to: 0perate upon the recording; of the firstidigit of a designation, a series. of transfer. relays one of which is associated-withieachgroup of register elements and arranged to'operate upon the operationofits associated register elements to associate the-=register elements for the next digit of the designation with the recording keys.

13. In a. telephone system, 2111; impulse transmitter including a single set'of recording keys, a unitary ,registering mechanismof the coordinate switch type having a;plurality of groups of register elements each arranged to register the digits of a designation recorded on said recording keys, means for transmitting series of impulses, 1 anda :setof counting relays operative under the control of said unitary registering mechanism .to, govern said transmitting means for effecting the transmission of series of impulses correspondingto-the digits recordedon said recording keys.

14. In a telephone exchange system, an impulse transmitter, a singleset of record'- ing keys, a unitary registeringnmechanism of the coordinate switchtype for registering the digits recorded on said recordingkeys, said registering mechanism haninga ,pl urality of groups of register elements arranged to respectively register the digits of recorded line designations, a set of counting relays operative under the control of. said plurality of: groups of register-elements for governing said impulse transmitter-to efiect the transmission of series ofv impulses-come spending to the digits re.corded,-. and; a series of transfer relays for progressively associ ments with said counting relays.

15. In a telephone exchange system, an impulse transmitter including a single set of recording keys, a unitary registerin nism of the cross-bar switch type for regis tering the digits recorded on said recording keys, a signal lamp, and means for lighting said lamp during the operation of said unitary registering mechanism.

16. In a telephone exchange system, an impulse transmitter, a single set of record.-'

ing keys, a unitary registeringmechanism of the coordinate switch type, said registering mechanism having a plurality of groups of register elements arranged to progressively register the digits of a line designation re corded on said keys, a set of counting relays, means for successively associating each of said groups of register elements with said counting relays, said counting relays operative under the control of each of said groups of register elements for governing said impulse transmitter-to effect the transmission of series of pulses corresponding to the digits registered in each of said groups of register elements, and means under the control of said counting relays to progressively release each of said plurality of groups of register elements upon the termination of a series of pulses corresponding to the registration set up in each of said groups of register elements respectively.

17. In atelephone exchange system, an impulse transmitter, a set of recording keys, a unitary registering mechanism of the cross-bar switch type operative in response to the depression ofsaid recording keys to register a line designation, a wipe out key, and means operative in response to the operation of said key to release said unitary registering mechanism.

18. In a telephone exchange system, an impulse transmitter, a single set of recording keys, a unitary registeringmechanism of the coordinate switch type for registering the digits recorded on said recording keys, said registering mechanism having a plurality of groups of register elements arranged to respectively register the digits of recorded line designations, a set of counting relays operative under the control of said plurality of groups'of register elements for mechagoverning said impulse transmitter to effect the transmission of series of impulses corresponding to the digits recorded, a series of transfer relays, means for progressively operating said transfer relays to successively associate each of said plurality of groups of register elements with said recording keys during the recording of a designation, and means for thereafterprogressively releasing said transfer relays for successively associ ating each of said plurality" of groups of' register elements with said count-ing relays. 19. In a telephone exchange system, an

impulse transmitter, a single set of recordingkeys, a unitary registering mechanism of the coordinate switch type for registering 7 the digits recordedon said recording keys,

said registering mechanism having a pluralplurality of groups of, register elements for governing said'impulse transmitter to effect the transmission of series of impulses corresponding to the digits recorded, a series of transfer relays, means for progressively opl erating said transfer relays to successively I associate each of said plurality of groups of register elements withsaid recording keys during the recording of a designation, and means. for thereafter progressively releasing said transfer relays in the order in which they were operated for successively associating each'of said plurality of groups of register elements with said counting relays.

20. In a telephone exchange system, an impulse transmitter including a single set of recording keys, a unitary registering mecha nism of the coordinate switch type having a plurality of register elements arranged in vertical and horizontal groups, a vertical op erating magnet associated with each vertical group of elements and a horizontal .mag net associated with each horizontal group of elements, each-of said vertical magnets being individual to and operable through con-r tacts ofone of said keys, a series of transfer relays, said relays being paired with said horizontal magnets, and means under the control of said vertical magnets to progressively operate said pairs of horizontal mag nets and transfer relays to render said horizontal groups of register elements operable upon successive actuations of said ke s.

In witness whereof, I hereunto su scribe my name this 12th day of June A. D. 1924. ROBERT W. HARPER. 

